Facsimile scanning system



Jun 11, 1940. w. G. H. FINCH 2,204,271

FACSIMILE SCANNING SYSTEM Filed June 26, 19257 2 Sheets-Skeet 1 IA E E-E 1 3 j INYENTOR.

Fi 2 william gh7i inch BY Y ATTORNEY.

June 11, 1940.

i w. 'G. H. FINCH FACSIMILE SCANNING SYSTEM Filed June 26, 1937 2 Sheets-Sheet 2 r l m 1 mill...- IIIIIIII- INVENTOR.

william gu7fl -gl'nch Patented June 11, 1940 UNITED STAT-ES PATENT -OFFICE FACSIMILE SCANNING SYSTEM William G. n. Finch, New York, N. Y.

Application June 26, 193v, Serial No. 150,489 5 Claims. (Cl. 64-27) This invention relates to facsimile systems and more particularly relates to novel apparatus for providing smooth scanning at the record sheet.

In a facsimile transmitter or receiver the rec- 0rd sheet is scanned line byline at a predetermined rate. In commercial operation rate of scanning generally ranges between 50 and 100 lines a minute. The operation of the scanner is. by means of a motor with gear-down mechlQ anism between the motor and the scanner. It has been found that gearing arrangements for driving the scanner mechanism cannot satisfactorily provide smooth operation of the scanner,

particularly scanners of start-stop type receivers. II The vibrations set-up in the drum due to the starting and stopping thereof, in conjunction with gearlngrattle between the continuously rotating motor and the drum, cause striations to appear on the recorded picture. striations traceable to $0 the actual gear arrangements appear as alternate dark and light parallel streaks-transverse to the as striations on the record sheet will be practically eliminated. I v

Accordingly, it is an object of my present invention to provide novel method of and means for driving a facsimile scanner mechanism.

A further object of my present invention is to provide novel meth of and'apparatus for cou-' pling a scanner mec nism to a driving member for smoothing out fluctuations in the scanner movement. f I

A further object of my present invention is to provide a novel method of and means for operating'a rotating drum scanner of a facsimile system.

These and further objects of my present invention will become apparent in the following description of preferred forms for carrying out my invention taken in connection with the drawings; in which; '1 i Figure 1 is a plan-view of a facsimile recording unit embodying one form of 'my invention.

Figure 2 corresponds to the view taken along -2! in Figure 1.

Figure 3 is the cross-sectional view taken along 3. 3 of Figure 1 through the mechanical driving connection to the drum. Figure 4 is an end view of a modification for the mechanical coupling arrangement, which view corresponds to Figure 2.

Figure 5 is a cross-sectional view taken through themodified coupling arrangement of Figure 4. Figures 6 and 7 are end-views of Figure 4 taken respectively from the left and right sides thereof.

Figure 1 is a plan view of a preferred form of a picture recorder in conjunction with which my invention is employed. It is to be understood that different types of recording mechanisms illustrated iacsimile recorder is of the general type described in my Patent No. 2,047,863, which issued on July 14, 1936, entitled Telecommunications system, and specifically oi! the form disclosed in'my co-pending application Serial No.

may equally well be used with my invention. The I 84,426, filed JunelO, 1936, entitled Telepicture scanning systems. I

The recordsheet it ismounted upon a ro= tatable drum II by means of the sheet fastening members II. The rollers II are, used to facilitate smooth mounting of sheetv upon the drum. Drum II is removably mounted between the pointed spindle ll of the tailstock i5 and a shaft located within the housing It which is coupled to the drive motor I! energized by a local power source through connection leads i8.

The motor I] is driven near the predetermined synchronous speed and synchronizing mechanism (not shown) is used to maintain the drum 1 I in exact phase and synchronous relation with the corresponding transmitter drum by means of cyclic synchronizing signals. The drum H is preferably operated on the start-stop principle in response to the synchroninng signals which operate a clutch located within housing It. In the cated within the housing 22. The scanner carriage 2| is guided in the parallel tracks IL-ll' and is secured to the feed-screw 2| by operating the cam lever 25in a manner fully disclosed in mypatent and application referred to above.

. The received facsimile signals are caused to produce alight beam 26 varying inaccordance with the shading of the original picture being transmittedin order that the resulting picture traced upon the recording sheet Ill will correspond tween the drive plate 21 and the drum ll. 28 is preferably encased by a rubber layer 3| and is. fitted between two parallel leaf spring members 32-32 set into a recess 38in the drive spring members 32 'to rotate drum H.-

thereto. p

The picture drum flange of the drum ll. Figures 2 and 3 illustrate details of the mechanical filter coupling be- Pin plate 21.

The drive plate '21 is operated directly from the synchronizing clutch member (not shown) and is supported on the housing l6 by a roller bearins' fl.

porting the drum inits axis of rotation. The rotation of drive plate 21 applies a rotative torque directly to the pin 28 through the leaf .The flexibility or the springs :2 is properly proportioned. in conjunction with the rotative mass or inertia of the drum .II to smooth out the spurious vibrations thereof. I have found that a drum having a relatively large rotative inertia is preferable, and have illustrated a cylinder 35 of lead or other 'heavy material attached to the flange 30 to increase the inertia or mass of the normally hollow drum ll.

springs 32 and the'rubber covering 3|. The

' It is important to have the leaf springs 32 adjusted accurately tangent to the pin 28 at itsouter rubber surface covering 3| as illustrated in Figure.-2.- I have. provided a simple method for maintaining this adjustment by the tapered pin 38 set into a slotjl in the drive plate 21 centrally between the spring members 32. The taperedpin is forced'between the sides of the narrow slot 31 until the proper operation of the leaf springs 32 is attained. This separation corresponds to the tangential alignment of the flexibility inherent in the springs 32 and the 1 cylinder of rubber 3| acting co-jointly with the rotational mass of cylinder H has been found to practically eliminate the vibrational tendencies of the drum causing dark and light alternate striations on the record sheet thereby greatly enhancing the quality of the reproduction.

Figures 4 to 7 illustrate a modified form for carrying out my present invention. Figure 4 corresponds to the similar view of the first form shown in Figure- 2. The pin 28 corresponds to the same pin secured to the flange 30 of the drum f H shown in Figure 3. In this form the pin 25 is respective drive .plate sections 40 and 4|. The

sections of rubber 43 and 44 provide a cushioning action to the metallic pin 28 corresponding to the rubber casing 3| of the previous modification. The rubbercushioning action' serves as a suit- I 1| is coupl ed to the drive plate 21 by means of a pin 28 attached to the left A spindle 34 projects through the center of the drive plate Z'I for properly sup-j able contacting element between the metallic pin 28 and the metallic members of the drive plate 21a.

The pivotally supported plate member 4| is spring biased with respect to the member 40 by means of'a spring 45 mounted within the member v40. Spring 45 forces pin 46 against the surface 41 of the element 4|.

The tension on the spring 45 is adjusted by means of the set mounted in the member 48 and'projects against the surface 41 of the pivoted element 4|. It is to be noted that the set screw 50 coacts against the portion of the member 4| located above the pivot 42; and that the spring biased pin 46 acts against member 4| at a region below the pivot 42. A dynamically stable system is thereby afforded for carrying out'the purposes of the invention.

The instant modification is more substantial and permits a finer degree of adjustment than the former modification and has been found to provide very satisfactory mechanical filtering action for the picture. drum. The flexible connect'ion action of the drive plate 210. is provided bythe pivoted element 4| mounted within the member 40, and the spring biasing of the pivoted member 4| within the member 40. The combination of the flexible driving connection with the rotative inertia of thegdrum serve to smooth out small variations or vibrations in the motivation ofthe drum ll.

Although I have illustrated preferred forms for carrying out my invention it is to be understood that modifications thereof are feasible and accordingly I do not intend to be limited thereby except as set forth injthe following claims.

I claim:

l. A mechanicalqilter arrangementbetween a driving means and driven means comprising a member operable by said driving means, said member having a first element, a second element pivotally supported by said first element, said first and second elements having opposed surface portions, and a pin attached to said driving means and arranged to coact with said elements between the opposed surface portions thereof.

'2. A mechanical filter arrangement between a driving meansfand driven means comprising a member operable by said driving means, said member having a first element, a second element pivotally supported by said first element.

said first and second elements having opposed surface portions containing cushions at a region beyond the center of rotation of said member, and a pinattached to said drivingmeans beyond the center of rotation thereof and arranged to coact with said elements between the opposed cushioned portions thereof.

. 3. A mechanical filter arrimgementbetween a driving means and driven means comprising a member operable by said driving means, said member having a first element, a second element pivotally supported by said first element said first and second elements having opposed'surface portions, means for imparting elastic pivotal relation between said first and second elements', and'a pin attached to said driving means and arranged to coact with said elements between the opposed surface portions thereof.

4. A mechanical filter arrangement between a member having ,afirst element, second eledriving means and driven-means comprising a member operable by said drivim means, said member having a first element, a second element pivotaily supported by said first element, said first and second elements having opposed surface.

. .portionseontaining cushions at a region beyond the center of rotation of said member, means for V imparting an elastic pivotal relation between saidflrstand second elements and-means mounted in said first element formitintaihing said termined amount, and a pin attached to said member operable by-said driving means, said ment pivotally supportedby said. first-element; said first and secondelements having opposed surface portions at -a region beyond the center of rotation of said'member, a peg set in said first element and spring biased against said secondelement for imparting inelastic pivotal lation between .said and second elements, and a set-screw mounted in said first element arranged to abut said second element at a portion thereof opposite .the peg abutment'portion with cushioned surface portions. apart by a prederespect to the element pivotal supportfor' main- ,taining said opposeds'urface -portions'apart by a predetermined amount and am attached to said driving means beyond the center, of rota.

tion thereof and arranged to coact with said elements between the opposed surface portions 

